Viabilidade da incorporação de resíduos vitrificados de isoladores elétricos cerâmicos no processo de obtenção de revestimentos refratários produzidos a partir de concreto sílico-aluminoso

Abstract

With the approval of the 12.305/2010 law establishing the National Policy on Solid Waste (NPSW), all waste generated in Brazilian territory should be reduced, treated and reused within the concept of sustainable development. Electrical ceramic insulators, after its life cycle, lose their insulating functions, being necessary its replacement and statistics shows its disposal by the Brazilian energy concessionaires up to 30.000 tons every year. In this aspect, the proposal of an environmental more suitable destination is shown as an important field of study. In this work, it was proposed the technical evaluation of the incorporation of electrical ceramic waste in silico-aluminous refractory concrete for the production of refractory coatings. The electrical ceramic waste was comminuted, as well as analyzed the use of different particle sizes and the effects of heat treatment and hydraulic cures. The chemical properties of raw materials were characterized and it was determined physical properties (bulk density, apparent porosity, open pore volume and water absorption), mechanical properties (tensile and compressive strength at room temperature and diametrical compressive strength at high temperature), thermal properties (thermal conductivity in different temperatures), and morphological properties (by optical microscopy). The results did not advise the use of the refractory coatings produced for structural applications, since, with an increase of the electrical ceramic waste in the refractory concrete it was observed a significant decrease on mechanical properties. By optical micrographs, it was noticed that the shape, size and waste aggregate distribution in the ceramic matrix were responsible for the brittle-fracture of the formulations. However, the use of the produced coatings showed to be promising in applications in which the thermal insulation is required. [resumo fornecido pelo autor]